The Treatment for Adolescents with Depression Study (TADS) is a randomized controlled trial funded by the National Institute of Mental Health and conducted at 14 sites. A sample of 439 adolescents between 12 and 17 years of age with a diagnosis of major depressive disorder participated in TADS. Participants were randomly assigned to 1 of 4 treatments: cognitive behavior therapy (CBT), fluoxetine (FIX), cognitive behavior therapy in combination with fluoxetine (Combo), or pill placebo (PBO). In addition to primary outcome measures, several additional measures were included in the TADS dataset and will be available for secondary analyses. My research will look at the role of dysfunctional attitudes in the development of adolescent depression. Specifically, I will explore perfectionism as a possible predictor, moderator, and/or mediator of treatment response in terms of depression symptoms and suicidality. Longitudinal data will be available in approximately 1 year and will allow for the testing of models of relations between perfectionism, dysfunctional attitudes, and depression. These findings will contribute to the understanding of cognitive vulnerability for depression and mechanisms of treatment response in depressed adolescents. [unreadable] [unreadable] [unreadable]